Method of repairing a worn wobbler housing for a constant-speed drive

Abstract

The method of repairing a variable wobbler body for a constant-speed drive, rotatable upon a first axis wherein the normally flat control face has become worn and irregular in shape, and the axial bore and tapered clearance opening upon a second axis is out of round, comprising the steps of cutting the worn surface areas of the wobbler body, drilling a bore of increased diameter through the axial bore and clearance opening, making a wear plate insert including a body with a replacement flat control surface, a cylindrical shank having a bore terminating in an outwardly diverging clearance opening, press-fitting the wear plate into the cut out machined areas, lapping the wear control face to a flatness of 0.000050 inches, approximately with a finish of 8 RMS. The invention further includes a wobbler body having a pair of aligned journals rotatable upon a first axis, a bottom flat seat in the plane parallel to the first axis, and a cylindrical bore upon a second axis at right angles to the first axis. A preformed wear plate insert has a body, a flat annular control wear surface, and a cylindrical shank having a bore terminating in an annular outwardly diverging clearance opening, the wear plate being nested within a recessed portion of the wobbler body and secured thereto.

I claim: 
     
       1. A method of repairing a wobbler housing for a constant-speed drive, said housing being rotatable upon a first axis to a limited extent, with said housing including a bottom normally flat control face which has become worn and irregular in shape and further including an axial bore and tapered shaft clearance opening located upon a second axis which has become worn and out of round, comprising the steps of: (a) grinding the worn bottom control face in a plane parallel to said first axis to a uniform depth;   (b) turning the ground bottom control face to a preset dimension;   (c) drilling a cylindrical bore in the wobbler housing upon said second axis at right angle to the first axis to a predetermined diameter;   (d) grinding said cylindrical bore to a preset irregular shape;   (e) taking a preformed wear plate having a body, a flat control wear face with a opposed flat wearface undersurface, a cylindrical shank, a bore and a clearance taper;   (f) forming the exterior surface of the shank to a corresponding irregular shape;   (g) inserting the wear plate body into the machined wobbler housing with the irregular surfaces in registry and with the flat wear face undersurface of said body snugly bearing against the machined bottom face of said housing; and   (h) securing the wear plate body within the wobbler housing.   
     
     
       2. In the method defined in claim 1 further comprising said irregular shape being elliptical, for preventing rotation of said wear plate body relative to said wobbler housing. 
     
     
       3. In the method defined in claim 2, further comprising the step after grinding an elliptical surface into the bore of the wobbler housing of baking the machined housing at about 390 degrees F., plus or minus 10 degrees F., for about four hours. 
     
     
       4. In the method defined in claim 2, further comprising, in step (g), the elliptical surface of the shank of said body nesting with the corresponding elliptical surface of the bore of said wobbler housing. 
     
     
       5. In the method defined in claim 1, further comprising the step of securing of the wear plate body including heating the wobbler housing to about 200 degrees F., and press-fitting the wear plate body into the wobbler housing for a shrink fit and anchorage on cooling. 
     
     
       6. In the method defined in claim 5, further comprising the step after grinding an elliptical surface into the bore of the wobbler housing of baking the machined housing at about 390 degrees F., plus or minus 10 degrees F., for about four hours. 
     
     
       7. In the method defined in claim 1, further comprising the step after grinding an irregular surface into the bore of the wobbler housing: (h) baking the machined housing at about 390 degrees F., plus or minus 10 degrees F., for about four hours.   
     
     
       8. In the method defined in claim 1, further comprising the step of grinding the control wear face of said wear body flat within 0.0001 TIR. 
     
     
       9. In the method defined in claim 8, further comprising the step of finish lapping the control face of said body to a flatness of 0.000050 inches, approximately. 
     
     
       10. In the method defined in claim 1, further comprising an intermediate step after step (f) of coating the premanufactured replacement wear plate body with a thin film of a sealant on all internal mating surfaces of a uniform thickness and the further step of allowing the sealant to cure. 
     
     
       11. In the method defined in claim 10, further comprising said sealant being Loc-Tite 620™. 
     
     
       12. In the method defined in claim 1, further comprising the shank of said wear plate body having an annular mount flange of uniform predetermined thickness which corresponds to the thickness of the metal removed from the wobbler housing in accordance with steps (a) and (b). 
     
     
       13. In the method of claim 12, further comprising the dimensions of said wear plate shank, bore and clearance taper being predetermined, with said wear plate cylindrical shank replacing the metal removed from the housing in accordance with step (c). 
     
     
       14. In the method defined in claim 1, further comprising the dimensions of said wear plate cylindrical shank, bore and clearance taper being predetermined, with said wear plate cylindrical shank replacing the metal removed from the housing in accordance with step (c). 
     
     
       15. In the method of claim 1, further comprising the intermediate step after step (c) of: further grinding said bottom control face to a final predetermined dimension for a preset flatness and surface finish.   
     
     
       16. In the method of claim 1, further comprising the intermediate step after step (c) of: chamfering the inside annular corner of the junction of said bottom control face and bore to minimize stresses in said body.